Translating paper machine tube roll



June 8, 1937. w. c. NASH TRANSLA'IVIN'G PAPER MACHINE TUBE ROLL Filed July l1, 1956 Patented June 8', 1,937v

UNITED STATES PATENT oEFlcE TEANSLATING PAPER MACHINE TUBE ROLL Application July 11, 1936, serial No. y90,115

4 Claims.

lI'his invention comprises a continuation in part of applicants co-pending application, Serial No. 49,469, filed November 3, 1935 and relates to improvements in paper making machines, and refers specifically to an improvement in the tube rolls of a paper making machine of the Fourdrinier type, characterized in that the rotative speed of the tube rolls is controllable independent of the speed of translation of the Fourdrinier wire and, that the tube rolls create no undue disturbance of formation of the web upon the wire.

In the making of paper on a Fourdrinier type of machine, the pulp predominantly liquid, is discharged from the head box on to a moving Wire or screen. The wire or screen passes over a series of tube rolls which contact the lower fa'c'e of the screen and assist in the removal of the liquid from the pulp carried on the upper portion of the Wire. The tube rolls are usually of relatively small diameter and are rotated by their contact with the moving screen.

4Of course, since the tube rolls are rotated by their contact with the screen, the peripheral speed of the surfaces of said rolls will be substantially equal to the speed of travel of the screen, and the angular velocity of said rolls will depend upon the speed of travel of the screen and the diameter of the rolls. erating the paper making machine at low speeds, the screen, of course, travels at relatively low speed and, hence, the tube rolls are not rotated at an excessive angular velocity. However,` as. the speed of travel of the screen increases, thereby increasing the angular velocity of the rolls, diiiculty is encountered due primarily to centrifugal action of the rolls upon the liquid carrier of the pulp which seeps through the screen on to the rolls, and also upon the fact that the front sides of the rolls travel upwardly toward the screen and the rear or trailing sides of the roll travel downwardly and away from the screen. These phenomena, although present at all screen speeds, are accentuated at high speeds and tend to disturb the ideal formation of the fibres upon the screen. Further, due to the fact that this disturbance is caused by the combined eiect of the liquid carrier and the Vspeed of the rolls, it will be most pronounced at those rolls adjacent the hea-d box since the pulp is dehydrated at a greater rate at its initial vtravel upon the Wire than at the intermediate or final portion of its travel.

My invention is broadly directed to the elimination of this diliicultyand resides in the pro- When opvision of means for controlling the rate of rotation of the tube rolls, particularly those adjacent the head box. In other Words, by thefuse of my invention, one of the above mentioned factors which cause disturbance of the fibres upon the screen is controllable.

To reduce the speed of the tube rolls, that is, to render the speed of the tube rolls independent ofthe lspeed of travel of the screen, I provide an Iarrangement whereby the axes of the tube rolls canl be moved at a desired rectilinear speed in the direction of travel of the screen or contrary to the direction of travel of the screen. By correlating the speed of translation of the rolls with the speed of translation of the screen, the rolls can be caused to rotate at a peripheral speed substantially equal to the difference of said speeds of translation. 'I'his difference in speed may be either positive or negative, that is, if the speed of translation of the screen exceeds the translation speed of the rolls, the rolls will rotate at a peripheral speed equal to the difference in the direction of travel of the screen, or if the translation speed of the rolls exceeds the speed of the-Web the rolls will rotate in the opposite direction to the direction of travel of the screen. However, in controlling the rate of rotation of the rolls, as described, the ultimate function of the rolls, that is, to :assist in the removal of the liquidl carrier, is in no Wise diminished.

Specifically my invention resides in the provision of an endlessly moving articulated conveyor upon which the tube rolls are mounted, the rolls being so mounted on the conveyor that the same may be periodicallymoved to position beneath the forming Wire or screen without jarring or shaking the Wire and disturbing the formation of the libres carried upon the Wire.

Other objects and advantages of my invention will be apparent from the accompanying drawing and following detail description.

In the drawing, Fig. 1 is a diagrammatic View of my improved tube roll arrangement.

Fig. 2 is a fragmentary sectional View taken on line 2-2 of Fig. 1.

Referring in detail to the drawing, I indicates one of two oppositely disposed side frames which may be positioned on opposite sides of a portion of the wet end of a paper making machine 2. A hanger 3l carrying an open bearing 4 is mounted upon an end .of each of the frames l in which opposite ends of shaft 5 are journalled, said shaft carrying breast roll 6. lA Fourdrinier Wire or screen 'l passes around breast roll 6 in the conof the driving of screen 1 and,l as will be hereinafter more fully described, the speed ofy the--l ventional manner and travels inthe direction indicated by the arrow.

A sprocket wheel 8 may be mounted upon each side of the machine 2 adjacent the breast roll 6 and a sprocket chain 9 may travel around each of said sprocket wheels. In spaced relationship with `each of the sprocket wheels 8 along the length of the machine 2, is a'sprocketV wheel I0, over which each of the chains passes. Sprocket chains 9 at the upper portion of their travelmov in the same direction as screen 1, eitherwheels 8 or I0 constitutingthe driving wheels. However, the driving of the sprocket wheels is lindependent chains-9 and screen 1 is different so that there will be relative motion between the two.

machine is mounted upon a shaft IIwhich is journalled in a bearing block I2, each `of which,

in turn, is slidably positioned in waysorguides I3 formedupon the support- I4. Ascrew I5 operable lby means of hand wheel I6 isthreaded in thek ends of the guides I3, and theends of said screws are so associated'with the blocks I2 that manipulation of hand wheels II'move blocks I2` within-.the ways I3.` By this. arrangement the desired tension'may be vproducedin chain 9.

The chains9 carry aplurality of tube-rolls I1 whichare mounted uponshafts [I8 atspaced intervals along the ,lengthof the` chains. AsY an important feature of my` invention theends ofshaftsl I8. comprise axes of articulation ofA the sprocket chains 9, that is, said ends serve as pivot .pins which connect spaced links of the chains to adjacent links. The importance .of this feature of my invention will be hereinafter` more fully described. I y y The ends vof the lshafts I9 extend beyond the chains 9; and carry frictionless, rollers. I9. Y AA frame 29mounted upon frame I traverses a porf immediately `thereafter aquantity of `pulp from thehead box (not shown) is flowed upon: the wire.1f-The pulp, of course," immediately begins to dehydrate, thatis, the liquid carrier` flows through the meshesof the wire leaving the fibres deposited upon the wire surface. In the :usual Fourdrinier machine` the wire carrying the`pulp passes over, and iis vsupportedbya plurality of tube or table rolls, which are freely rotatable about their axes butare laterally immovable.

Said tube rolls are rotated bymovement of the wire and, hence, are rotated r"at relatively high speed when the papermaking operation israpid. Therefore, a portion of the liquidv `discharged through the screensurface is carried upon the surfaces of theserapidly moving rolls and by centrifugal force is thrown from the rolls at a rapid 'rate upwardly toward thegbottom of the wire thus tending to disturb the fibres upon the upper surfaceL-of 'the wire. In` additionthis rotating action; ofthe tube rolls'builds up pressure Vzones adjacent the screen at the advancing side of the rolls, and reduced pressure zones adjacent the screen at the receding side of the rolls. The pressure zone tends to lift the fibres from the screen surface and otherwise disturbs the original desired lay of the fibres. The reduced pressure zone tends to suck'the fibres down upon the wire surface which causes objectionable wire marks upon the paper. In addition, pin holes are i-formed and a one-sided shade is imparted to colored paper. Consequently, the tube rolls of the 'conventional paper making machine constitute one of the most serious limitations to the speed of the machine. l

Y It can readily be seen therefore, that by controlling'the rate of rotation of the rolls I1 independent of the speed of the wire 1, the difficulties attending the rapidly rotating tube rolls are overcome. vIn addition, the tube rolls may be rotated as 'slowly or as rapidly as desired by merely controlling the speed of the chains 9 with respect to t,he;-wire.1.v The chainsmay be driven by any suitable variable speed drive (not shown). For example, with` a yscreen speed of 1200 feet per minute, chains 9 may bedrivenat a. speed of 1150 orl250 feetper minute. -In' the former case the rolls I1 will be so rotated as to have a peripheral speed of 50 feet per minute in a clockwise or positive direction and in theJatter. casethe rolls will have a peripheral speed of 50 feet per minute ina counterclockwiseor negative direction. Of

course, any desired difference of screen speed or` chain speed may be adopted andthe above example is; not to be construed-as a limitation.

In view o f` the fact that the` difhculty hereinbefore described has two factors, namely, roll speed andthe presence of liquid carrier on or adjacent the rolls, the disruptive effect of the rapid.

rlyrotating rollswill not be as pronouncedwhen the Aratemf dehydrationiof the vpulp upon the screendecreases below a critical point.v Consequently, it maybe necessary to mount only that portionof. the tube, rolls of the machine Hadju.- cent the breast roll .upon the endless chains. For instance, it may be foundsumcient to mount only those tuberous within 6 `or s :een upon` the breast Vroll of the ,moving chain. However, my

invention broadly contemplates mounting all, or a numberyless than all, .upon a moving carrier.

As a feature of mvv present invention, the wire 1` carried by the translated tube rolls is maintained as undisturbedfandquiescent as possible. A lserious problem is `presented in bringing the tube'rolls I1 into initial contact with the lower surface of the screen whensaid rolls are carried byan articulated conveyor such as the chains 9. 'I'he links of the chain being straight must of necessity-merely approximate the curvature of the sprocket wheel 8. Consequently,.I have journalled the roll shafts I8 at axes of articulation of the links. By this arrangement, although the links of the chains willdispose themselves along chordal lines when the chains travel over the sprocket wheels, the pivotal axes of the rolls will describe a true circular path. Hence, rolls I1 will be brought into supporting contact with the screenv or wire 1 at thetop of sprocket wheels 8 alonga line or plane tangent to the arc described by the outermost-surfaces of 'said rolls in passing :around sprockets 8. Therefore, the screen carrying ther newlylaid fibers will not be jarred bythe' rolls coming into contact with the wire which action, of course; would disturb the vfiber formation. i* v f I= claim as my invention:

l. In combination, a paper making machine comprising a frame, an endlessly moving paperforming screen carried by said frame, a plurality of rotatable tube rolls over which said screen moves and upon which said screen is supported, a, sprocket chain conveyor for moving said tube rolls laterally in a plane parallel to the plane of motion of said screen, said tube rolls being journalled in the links of said chain, the axes of said tube rolls being in a plane substantially coincident with the plane of the axes of the pintle pins of said chains, said frame being provided with a channel opening towards, and on each side of said conveyor, said channels paralleling a portion of the path of travel of said screen, a, bearing carried at each end of each of said tube rolls adapted to travel in said channels whereby movement of said tube rolls at right angles to said channels is limited.

2. In combination, a paper making machine comprising a frame, an endlessly moving paper forming screen carried by said frame, a plurality of rotatable tube rolls over which said screen moves and upon which said screen is supported, a conveyor comprising two oppositely positioned endlessly moving chains, said tube rolls being rotatably carried between said chains, the axes of said tube rolls being positioned in substantially the plane of the longitudinal axes of said chains, said frame being provided with a channel opening towards, and on each side of said conveyor, said channels paralleling the upper run of said screen, a bearing carried at each end of each of said tube rolls adapted to travel in said channels whereby movement of said tube rolls at right angles to said channels is limited.

3. In combination, a paper making machine comprising a frame, an endlessly moving paper forming screen carried by said frame, a plurality of rotatable tube rolls over which said screen moves and upon which said screen is supported, a conveyor comprising two oppositely positioned endlessly moving chains, said tube rolls being rotatably carried between said chains, the axes of said tube rolls being positioned in substantially'the plane of the longitudinal axes of said chains, said frame being provided with a channel openingtowards, and on each side of said conveyor, said channels paralleling a portion of the path of travel of said screen, a bearing carried at each end of each of said tube rolls adapted to travel in said channels whereby movement of said tube rolls at right angles to said channels is limited.

4. In combination, a paper making machine comprising a frame, an endlessly moving paper forming screen carried by said frame, a plurality of rotatable tube rolls over which said screen moves and upon which said screen is supported, a conveyor comprising two oppositely positioned endlessly moving chains, said tube rolls being journalled in said oppositely positioned chains and being disposed between said chains, said frame being provided with a channel opening towards, and on each side of said conveyor, said4 channels paralleling the upper run of said screen, a bearing carried at each end of each of said tube rolls adapted to travel in said channels whereby movement of said tube rolls at right angles to said channel is limited.

WILLIAM C. NASH. 

